Transposition of the great arteries

• abnormal septation of conus and aortopulmonary (truncus) valve

• aortic valve arises to the right of and anterior to pulmonary valve, so the aorta rises from the right ventricle

• pulmonary trunk arises from the left ventricle

• therefore, there are parallel, non-communicating circuits

• patients present with cyanosis and heart failure

• if oxygen is given, the ductus arteriosus will close and the patient will die

• surgery is required: septostomy: balloon or surgical

• arterial switch operation is also performed, in which the pulmonary artery and aorta are switched. this is difficult because of the coronary arteries

diagram of transposition

• blood goes from right atrium to right ventricle, aorta, out to systemic circulation, back via vena cava, and circles again

• other pool of blood goes from left atrium to left ventricle, out to lungs, back into left atrium, and circles

gross specimen

• pulmonary trunk is left and posterior; arises from left ventricle

• aorta arises from right ventricle

Category: Pathology Notes